I have CovaChilli running on OpenWRT 8.09_RC1 on a Linksys WRT54GL. I got WPA working (kind of) with the original ChilliSpot 1.1 with these options:

radiusserver1 192.168.1.10<br />
radiusserver2 192.168.1.10<br />
radiussecret XXXX<br />
dhcpif br-lan<br />
eapolenable<br />
proxylisten 127.0.0.1<br />
proxyport 1645<br />
proxyclient 127.0.0.1<br />
proxysecret XXXX

This doesn't work with CoovaChilli. Also I have actually no idea what the difference between "proxylisten" and "proxyclient" is...